<!DOCTYPE html>
<html lang="zh-CN">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>css特效</title>
    <style>
        *{
            margin: 0;
            padding: 0;
            box-sizing: border-box;
            font-family: 'fangsong';
        }
        body{
            height: 100vh;
            display: flex;
            align-items: center;
            justify-content: center;
            background-color: rgb(0, 0, 0);
        }
        .item{
            position: relative;
            margin: 50px;
            width: 300px;
            height: 80px;
            text-align: center;
            line-height: 80px;
            text-transform: uppercase;
            text-decoration: none;
            font-size: 35px;
            letter-spacing: 5px;
            color: aqua;
            overflow: hidden;
            -webkit-box-reflect: below 1px linear-gradient( transparent,rgba(6, 133, 133,0.3));
        }
        .item:hover{
            background-color: aqua;
            box-shadow:0 0 5px aqua,
            0 0 75px aqua,
            0 0 155px aqua;
            color: black;
        }
        .item span:nth-of-type(1){
            position: absolute;
            left: -100%; 
            width: 100%;
            height: 3px;
            background-image: linear-gradient(to left,aqua ,transparent);
            animation: shang 1s linear infinite;
        }
        @keyframes shang{
            0%{
                left:-100%;
            }
            50%,100%{
                left:100%;
            }
        }
        .item span:nth-of-type(2){
            position: absolute;
            top: -100%;
            right: 0;
            width: 3px;
            height: 100%;
            background-image: linear-gradient(to top,aqua ,transparent);
            animation: you 1s linear infinite;
            animation-delay: 0.25s;
        }
        @keyframes you{
            0%{
                top:-100%;
            }
            50%,100%{
                top:100%;
            }
        }
        .item span:nth-of-type(3){
            position: absolute;
            right: -100%;
            bottom: 0;
            width: 100%;
            height: 3px;
            background-image: linear-gradient(to right,aqua ,transparent);
            animation: xia 1s linear infinite;
            animation-delay: 0.5s;
        }
        @keyframes xia{
            0%{
                right:-100%;
            }
            50%,100%{
                right:100%;
            }
        }
        .item span:nth-of-type(4){
            position: absolute;
            bottom: -100%;
            left: 0;
            width: 3px;
            height: 100%;
            background-image: linear-gradient(to bottom,aqua ,transparent);
            animation: zuo 1s linear infinite;
            animation-delay: 0.75s;
        }
        @keyframes zuo{
            0%{
                bottom:-100%;
            }
            50%,100%{
                bottom:100%;
            }
        }
        .item1{
            filter: hue-rotate(100deg);
        }
        .item3{
            filter: hue-rotate(250deg);
        }
    </style>
</head>
<body>
     
        <a href="#" class="item item1">
            DODOD
            <span></span>
            <span></span>
            <span></span>
            <span></span>
        </a>
        <a href="#" class="item item2">
            DODOD
            <span></span>
            <span></span>
            <span></span>
            <span></span>
        </a>
        <a href="#" class="item item3">
            DODOD
            <span></span>
            <span></span>
            <span></span>
            <span></span>
        </a>
 
</body>
</html>
